During link planning such factors as distance, obstacles and the link margin should be taken into account. We strongly recommend to use the InfiPLANNER tool for link planning.
InfiPLANNER is a link planning tool, which allows to design networks using InfiNet Wireless devices for optimal deployment and cost effectiveness. It performs different scenarios based on geography, distance, antenna height, transmit power, device models and other factors. It outputs an installation report that defines the parameters to be used for configuration, alignment and operation. Use the installation report to compare predicted and actual link performance. InfiPLANNER is available at https://infiplanner.infinetwireless.com.
You can find more detailed information about InfiPLANNER in the "InfiPLANNER: Link Planning Tool" online course.
Range and Obstacles
Make sure line of sight is provided during planning the antennas placement for a point-to-point link, to achieve maximum range and performance between two antennas. Perform a survey to identify all the obstructions (such as trees or buildings) in the path and to assess the risk of interference.
The radio beam is an invisible form of electromagnetic wave propagation and is not as thin as a laser beam, for example. The main energy in a radio beam is concentrated along the straight line between the two antennas, inside an area the shape of an ellipsoid (or a rugby ball). This area is called a 1st Fresnel zone and its exact form and size depends upon the frequency and the signal propagation path length.
If most of the 1st Fresnel zone is obstructed, a major part of the radio wave’s electromagnetic energy is lost, which leads to a severe signal quality degradation and as a result to decreased coverage range or performance.
Below is an incomplete list of possible obstructions on the signal propagation path:
- Neighboring buildings.
- Power lines.
To obtain the best results, it is necessary to perform a precise analysis of the signal propagation path and possible obstructions that may cover the 1st Fresnel zone.
More detailed information about radio signal propagation is available at "Wireless Networking Fundamentals" online course.
General recommendations for antenna placement:
- Try to keep the LOS clear of obstructions. In case of installations over vegetation and forest, make sure the direct LOS stays above the trees; in urban environments - above the tallest buildings along the radio path.
- The influence of trees can be variable, depending on seasons (ice, dew, leaves). Keep in mind that, during spring and summer, leaves can absorb high levels of radio energy. Therefore, when installing during the cold season, over forests and trees without leaves, try to achieve a higher fade margin.
- Install antennas as far as possible from other antennas (the recommended distance is at least 2 meters).
- Reflecting surfaces should be considered (buildings with reflective windows, water surfaces or wet grounds). These can be useful in NLOS situations, if there is no direct clear path between the 2 antennas, so the radio signal needs to be reflected off a surface. However, these can also decrease the signal quality when encountered along a clear LOS link, because of fading caused by multipath.
- When installing antennas over water, tune the height bracket within 1-3 meters range variation, because it can yield significant signal level variations due to multipath fading.
- Weather factors such as rain or snow do not usually affect system performance. If seasonal changes influence the signal quality, then the connectors probably are not protected well enough from humidity, or the cables, connectors or antennas are covered by vegetation during summer or ice during winter.